Experimental and DFT Computational Insights on the Adsorption of Selected Pharmaceuticals of Emerging Concern from Water Systems onto Magnetically Modified Biochar

This work aimed to fabricate a magnetically modified biochar (MBC) through one-step pyrolysis of Vitex doniana nut at 500 °C and investigate its feasibility for the removal two pharmaceuticals, namely, amoxicillin (AMX) trimethoprim (TMT) from aqueous environment. The textural characteristics, chemical composition magnetic properties MBC were analyzed using Brunauer-Emmett-Teller (BET) analysis, scanning electron microscopy (SEM), Fourier Transform Infrared (FTIR) spectroscopy, X-ray diffraction (XRD) vibrating sample magnetometer (VSM). results demonstrated successful incorporation particles in matrix. specific surface area average pore volume obtained as 108.90 m2/g 2.98 cm3/g, respectively. adsorption process was observed be strongly pH-dependent, equilibrium attained within 1 h. kinetic data favors pseudo-second-order model (R2 > 0.999), implying that most plausible mechanism chemisorption. isothermal best fitted by Langmuir 0.985), signifying mainly monolayer on homogeneous surface. maximum capacity achieved AMX TMT 41.87 55.83 mg/g 303 K, thermodynamic examination highlighted feasible accompanied with absorption heat increase entropy both adsorbates. Furthermore, exhibited good recycling capability such decreases ~ 25% after reuse six cycles. Besides, theoretical based density functional theory (DFT) calculations molecules (ΔE = 3.762 eV) are more reactive compared 3.855 which correlates experimental observations.